Communication system, communication control method, and master station communication device

Abstract

To achieve more efficient resource allocation in a radio access network of a mobile communication network. [Solution] The present invention relates to a communication system having a plurality of wireless antenna devices that transmit and receive wireless signals to and from mobile terminals, and a signal processing device that processes transmission and reception of signals to and from the mobile terminals via the wireless antenna devices.The communication system of the present invention is characterized by comprising: allocation means for allocating a communication rate and a communication method to an area corresponding to each of the wireless antenna devices; and area merging means for performing area merging processing to merge the reference area and merging candidate areas into a single merged area and allocate a communication rate and a communication method to the merged area when the communication methods of the reference area and the merging candidate areas match and the sum of the required bandwidth of the reference area and the merging candidate areas is equal to or less than a selectable communication rate.

Description

[Technical Field]

[0001] The present invention relates to a communication system, a communication control method, and a master station communication device, and can be applied to a network of a wired section on the upper side (core side) from a wireless antenna connected to a mobile terminal (for example, a mobile phone terminal), for example. [Background technology]

[0002] In conventional mobile communication networks (communication carrier networks), wireless base stations are divided into substations that communicate with user devices and a master station that controls the substations. Furthermore, in conventional mobile communication networks, the master station and substations are connected by optical fiber, and multiple wireless devices are installed within each wireless base station. Furthermore, in conventional mobile communication networks, the number of wireless devices per wireless base station is determined by the number of mobile terminals that the wireless base station must handle and the amount of traffic that is set based on a predicted frequency of use. Furthermore, in conventional mobile communication networks, mobile terminals must be able to connect to and use wireless base stations even during periods of high traffic, resulting in a significant number of wireless devices.

[0003] On the other hand, traffic generated by mobile communication networks generally fluctuates depending on the time of day, with low traffic late at night and early in the morning and high traffic from daytime to night. Furthermore, with the launch of 5G services in recent years, high-definition image transmission services and services aimed at advancing cities using digital twin technology have become widespread. As such, mobile communication network services are now becoming more and more diverse with high capacity, and traffic differences are becoming increasingly large.

[0004] In mobile communication networks, wireless base stations are usually installed assuming high traffic times, and operate even during low traffic times, which can result in unnecessary power consumption. Therefore, wireless base stations that make up mobile communication networks are required to operate efficiently, with power consumption reduced as much as possible.

[0005] In recent years, as the speed of wireless access networks provided by mobile communication networks has increased, the area (cell) covered by a base station device has become smaller, and as a result, the number of base station devices that need to be installed to configure a mobile communication network has increased. For this reason, conventional mobile communication networks have introduced passive optical network (PON) systems, in which multiple subscribers share a single optical transmission line, as networks to accommodate multiple base station devices.

[0006] In a PON system, one optical line terminal (OLT) installed at a telecommunications carrier's central office is connected to multiple optical network units (ONUs) on the subscriber side via an optical splitter. The OLT dynamically allocates upstream bandwidth to multiple ONUs, for example, 32 ONUs, using time division multiplexing (TDMA), thereby achieving high bandwidth utilization efficiency. 10Gbps-class PON systems are currently being introduced in optical access networks.

[0007] As power saving technologies for the wireless access network using the PON, there are technologies described in Patent Document 1 and Non-Patent Document 1.

[0008] The technology described in Patent Document 1 enables a reduction in power consumption across the entire network by controlling the sleep of ONUs connected to small cell base stations in a wireless access network of a mobile communication network so that the sleep control of the small cell base station with a small number of linked mobile terminals is coordinated with the sleep control of the small cell base station.

[0009] Non-Patent Document 1 describes a method for allocating optimal optical communication devices (communication methods and communication rates) in accordance with traffic volume in an optical wireless network.

[0010] Non-Patent Document 1 describes a communication control method in which a 250m mesh area is assigned as a cell area, and the optimal communication rate / communication method is assigned according to the required bandwidth of each mesh area (ONU). In the communication control method described in Non-Patent Document 1, if there is a mesh area with a significantly low required bandwidth, the reference mesh area (reference area) and its adjacent mesh area (adjacent area) have the same communication rate / communication method, and the sum of the required bandwidths of the reference area and adjacent area is equal to or less than the communication rate of the selected optical communication device, the adjacent area is merged into the reference area to form the same area. This reduces the number of ONUs that operate simultaneously, thereby reducing power consumption. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Application Publication No. 2018-207457 [Non-patent literature]

[0012] [Non-Patent Document 1] "Study on Low Power Consumption by Optimizing Communication Rate in PON Systems for Mobile Networks," Hiroyuki Saito et al., 2023 Institute of Electronics, Information and Communication Engineers Society Conference Summary of the Invention [Problem to be solved by the invention]

[0013] However, even if the technology described in Non-Patent Document 1 is used, if the optical communication specifications (e.g., communication rate or communication method) between the reference area and the adjacent area are different, they cannot be merged, and there are cases where inefficient bandwidth allocation is unavoidable, such as allocating a bandwidth with an excessive communication rate relative to traffic demand.

[0014] In view of the above problems, there is a demand for a communication system, a communication control method, and a master station communication device that can realize more efficient resource allocation in a wireless access network of a mobile communication network. [Means for solving the problem]

[0015] A first aspect of the present invention is a communication network system comprising a plurality of wireless antenna devices that transmit and receive wireless signals to and from a mobile terminal, a signal processing device that processes transmission and reception of signals to and from the mobile terminal via the wireless antenna devices, and data transmission between each of the wireless antenna devices and the signal processing device, wherein the communication network system has a slave station communication device connected to each of the wireless antenna devices, a master station communication device connected to the signal processing device, and a transmission path that connects the master station communication device to each of the slave station communication devices, the communication network system comprising: an allocation means that allocates a communication rate and a communication method to an area corresponding to each of the wireless antenna devices; and an area merge means that selects one of the areas as a reference area, and, if the communication method of the reference area and a merge candidate area adjacent to the reference area matches, and the sum of the required bandwidth of the reference area and the required bandwidth of the merge candidate area is equal to or less than a selectable communication rate, merges the reference area and the merge candidate area into a single merged area, and performs area merge processing to allocate a communication rate and a communication method to the merged area.

[0016] The second aspect of the present invention is a communication control method performed by a communication system comprising a plurality of wireless antenna devices that transmit and receive wireless signals to and from a mobile terminal, a signal processing device that processes transmission and reception of signals to and from the mobile terminal via the wireless antenna devices, and a communication network system that transmits data between each of the wireless antenna devices and the signal processing device, wherein the communication network system has a slave station communication device connected to each of the wireless antenna devices, a master station communication device connected to the signal processing device, and a transmission path that connects the master station communication device to each of the slave station communication devices. The communication system has an allocation means and an area merging means, wherein the allocation means allocates a communication rate and a communication method to an area corresponding to each of the wireless antenna devices, and the area merging means selects one of the areas as a reference area, and when the communication method of the reference area and a merge candidate area adjacent to the reference area match and the sum of the required bandwidth of the reference area and the required bandwidth of the merge candidate area is equal to or less than a selectable communication rate, merges the reference area and the merge candidate area into a single merged area, and allocates a communication rate and a communication method to the merged area.

[0017] The third aspect of the present invention is a communication network system that transmits data between a plurality of wireless antenna devices that transmit and receive wireless signals to and from a mobile terminal, and a signal processing device that processes transmission and reception of signals to and from the mobile terminal via the wireless antenna devices, and is characterized in that the system comprises: a master station communication device that connects the signal processing device to slave station communication devices connected to each of the wireless antenna devices via a transmission path; an allocation means that allocates a communication rate and a communication method to an area corresponding to each of the wireless antenna devices; and an area merge means that selects one of the areas as a reference area, and, if the communication method of the reference area and a merge candidate area adjacent to the reference area match, and the sum of the required bandwidth of the reference area and the required bandwidth of the merge candidate area is equal to or less than a selectable communication rate, merges the reference area and the merge candidate area into a single merged area, and assigns a communication rate and a communication method to the merged area. [Effects of the Invention]

[0018] According to the present invention, more efficient resource allocation can be achieved in a radio access network of a mobile communication network. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a block diagram showing the overall configuration of a communication system according to a first embodiment. [Figure 2] 10 is a flowchart showing an example of area merge processing performed by a communication control unit according to the first embodiment. [Figure 3] 1 is a diagram showing an example of an overall area configuration in map format according to a first embodiment. FIG. [Figure 4] FIG. 2 is a diagram illustrating an example of a model of power consumption on the RU / ONU side according to the first embodiment. [Figure 5] 5A and 5B are diagrams illustrating examples of power consumption according to the configuration of a merge area according to the first embodiment. [Figure 6] FIG. 1 is a diagram (part 1) showing an example of required bandwidths corresponding to each area according to the first embodiment. [Figure 7] FIG. 10 is a diagram (part 1) showing communication rates / communication methods provisionally assigned to each area by a communication control unit according to the first embodiment. [Figure 8] 4 is a diagram showing an example of an area merge processing route determined by a communication control unit according to the first embodiment. FIG. [Figure 9] FIG. 10 is a diagram (part 1) showing, in a table format, the results after the communication control unit according to the first embodiment has completed the area merge process. [Figure 10] FIG. 10 is a diagram (part 1) showing, in map form, the result after the communication control unit according to the first embodiment has completed the area merge process. [Figure 11] 10 is a diagram illustrating, in map form, a result after the area merge process is completed in a case where the communication control unit according to the first embodiment determines the area merge process route in order of area numbers. FIG. [Figure 12] FIG. 10 is a diagram (part 2) showing an example of required bandwidths corresponding to each area according to the first embodiment. [Figure 13] FIG. 10 is a diagram (part 2) showing communication rates / communication methods provisionally assigned to each area by the communication control unit according to the first embodiment. [Figure 14] FIG. 10 is a diagram (part 2) showing, in a table format, the results after the communication control unit according to the first embodiment has completed the area merge process. [Figure 15] FIG. 10 is a diagram (part 2) illustrating, in map form, the result after the communication control unit according to the first embodiment has completed the area merge process. [Figure 16] FIG. 10 is a diagram showing, in table format, the results of the area merge process when the communication control unit according to the first embodiment determines the area merge process route in the order of area numbers and does not change the communication rates provisionally allocated to each area. [Figure 17] FIG. 10 is a diagram showing, in map format, the results of the area merge process when the communication control unit according to the first embodiment determines the area merge process route in the order of area numbers and does not change the communication rates provisionally allocated to each area. [Figure 18] FIG. 10 is a diagram showing an example of an overall area configuration in the form of a map in the second embodiment. [Figure 19] FIG. 10 is a diagram illustrating an example of an area merge processing route determined for an area merge processing window by a communication control unit according to the second embodiment. [Figure 20] 10 illustrates an example of a result when a communication control unit according to the second embodiment performs area merge processing on an area merge processing window. DETAILED DESCRIPTION OF THE INVENTION

[0020] (A) First embodiment A first embodiment of a communication system, a communication control method, and a master station communication device according to the present invention will be described below in detail with reference to the drawings.

[0021] (A-1) Configuration of the First Embodiment FIG. 1 is a block diagram showing the overall configuration of a communication system 1 according to the first embodiment.

[0022] In addition, the reference numerals in parentheses in FIG. 1 are used only in the second embodiment described later.

[0023] The communication system 1 includes RUs (Radio Units) 30 (30-1 to 30-N) as N antenna devices (radio base stations) that constitute a radio access network in a mobile communication network, DU / CUs (Distributed Units / Centralized Units) 50 as signal processing devices that control each RU 30 to form the radio access network, an optical communication network system 100 as a communication network system that connects each RU 30 and the DU / CU 50 via optical communication (PON), and a ROADM 40 that connects the DU / CU 50 and the optical communication network system 100. The RUs 30 transmit and receive radio signals to and from mobile terminals TE that subscribe to the communication system 1 (mobile communication network). The DU / CU 50 also communicates with the mobile terminals TE via the RUs 30.

[0024] The optical communication network system 100 has an OLT 10 as a parent station communication device and N ONUs 20 (20-1 to 20-N) as child station communication devices. The OLT 10 is connected to an optical fiber 80, which is branched into N branches (to the number of ONUs 20) by a splitter 70, and each branch is connected to the ONUs 20-1 to 20-N. The configuration for branching the optical fiber 80 is not limited to the configuration in Fig. 1, and a configuration in which multiple splitters 70 are used to branch the optical fiber 80 in multiple stages (hierarchically) may also be used.

[0025] The ONUs 20-1 to 20-9 are connected to the RUs 30-1 to 30-N, respectively. A reconfigurable optical add / drop multiplexer (RADM) 40 serving as an optical add / drop device is inserted between the OLT 10 of the communication system 1 and the DU / CU 50. A core network 60 (e.g., a core network of a communication carrier) is connected above the DU / CU 50. The DU / CU 50 performs a DU function that performs physical layer processing of signals (e.g., modulation, demodulation, etc.) and MAC layer communication control, and a CU function that controls packet communication between the RU 30 and the core network 60 and manages radio resources for each RU 30.

[0026] In the communication system 1, each RU 30 is responsible for wireless communication within one mesh area, and connects to a mobile terminal TE within the cell under the control of the DU / CU 50. In this specification, for ease of explanation, the term "mesh area" is also abbreviated to simply "area."

[0027] Next, the internal configuration of the OLT 10 will be described.

[0028] As shown in Figure 1, the OLT 10 includes a communication control unit 11, an AWG 12, an OLT concentrator 13 (13-1, 13-2), M (M is an integer greater than or equal to 2) 10G transceivers 14 (14-1 to 14-M), a transceiver 15, L (L is an integer greater than or equal to 2) 25G transceivers 16 (16-1 to 16-L), a transceiver 15, and a transceiver 17.

[0029] The communication control unit 11 is responsible for the function of controlling communication in the entire OLT 10 .

[0030] The 10G transceiver 14 and the 25G transceiver 16 are optical transceivers capable of communication at 10 Gbps and 25 Gbps (EO / OE conversion possible), respectively. The combination of communication speeds and numbers of each transceiver / media converter is not limited to the above example, and various combinations can be applied.

[0031] In the OLT 10, an AWG 12 is connected to the PON side (optical fiber 80), and a transceiver 15 and a transceiver 17 are connected to the upper side (ROADM 40). The OLT concentrator 13-1 concentrates communications from the downstream 10G transceivers 14-1 to 14-M and connects them to the upper transceiver 15. The OLT concentrator 13-2 concentrates communications from the downstream 25G transceivers 16-1 to 16-M and connects them to the upper transceiver 17.

[0032] In the OLT 10, each transceiver / media converter is assigned to and connected to one of the ONUs 20 by the AWG 12. An ONU 20 connected to a 10G transceiver 14 or a 25G transceiver 16 by the AWG 12 is connected to the upstream side using the PtMP (Point to Multipoint) communication method. On the other hand, an ONU 20 connected to a 200G media converter 18 by the AWG 12 is connected to the upstream side using the PtP (Point to Point) communication method.

[0033] Next, the internal configuration of each ONU 20 will be described.

[0034] As shown in FIG. 1, each ONU 20 has a transceiver 22 for connecting to the upstream side (PON side) and a user-side interface 21 for connecting to the downstream side (user side / subscriber side) RU 30. The transceiver 22 communicates with the upstream side (PON side) at a maximum communication speed that is determined by a communication rate controlled by the OLT 10. The communication rate assigned to the ONU 20 (transceiver 22) by the OLT 10 (communication control unit 11) is the communication speed supported by the transceiver / media converter assigned by the OLT 10 (communication control unit 11). For example, if the OLT 10 (communication control unit 11) assigns the 10G transceiver 14-1 to the ONU 20-1, the communication rate of the transceiver 22 of the ONU 20-1 is 10 Gbps. In this case, the ONU 20-1 (transceiver 22) communicates with the upstream side at a communication rate of 10 Gbps using the PtMP method.

[0035] It is assumed that the communication control unit 11 of the OLT 10 holds information about each RU 30 (each area). The communication control unit 11 assigns an identification number (hereinafter referred to as an "area number") to each area (each RU 30) and manages the area. For example, if N=8, areas A-1 to A-8 (RUs 30-1 to 30-8) are assigned area numbers 1 to 8, respectively. It is also assumed that each communication control unit 11 holds information about the communication bandwidth requested by each area (each RU 30) (hereinafter simply referred to as a "requested bandwidth"). It is also assumed that the communication control unit 11 holds information about the positional relationship (map information) of each area. There are no limitations on the method by which the communication control unit 11 holds various information about each area (each RU 30) (hereinafter referred to as "area information"). For example, the communication control unit 11 may hold area information from an upper-level device that controls each RU 30 (for example, the DU / CU 50 or an orchestrator (not shown) on the core network 60).

[0036] 1, the communication rate (maximum communication speed) of the portion (including transceivers, etc.; hereinafter also referred to as "optical communication device") accommodating each area (ONU 20) on the OLT 10 side is either 10 Gbps or 25 Gbps in the case of PtMP. In other words, in the optical communication network system 100 of this embodiment, the communication rate that the communication control unit 11 can select for each area is either 10 Gbps or 25 Gbps in the case of PtMP communication method.

[0037] Here, the communication control unit 11 performs a process (hereinafter also referred to as "provisional allocation process") to provisionally allocate the communication rate and communication method for each area (mesh area) taking into consideration the required bandwidth of each area, etc. At this time, the method of the provisional allocation process is not limited, and various allocation methods (for example, conventional allocation methods described in Non-Patent Document 1, etc.) can be applied.

[0038] After the provisional allocation process for each area, the communication control unit 11 performs a process (hereinafter referred to as an "area merge process") to control each ONU 20, etc., to merge multiple mergeable areas to form one area (hereinafter referred to as a "merged area"). In other words, the merged area will be composed of multiple areas (mesh areas).

[0039] Next, an outline of the area merge process performed by the communication control unit 11 will be described.

[0040] The communication control unit 11 performs the area merge process by selecting an arbitrary area as the area that will serve as the basis for the area merge process (hereinafter referred to as the "reference area"), extracting areas that can be merged from areas adjacent to the selected reference area (hereinafter referred to as "adjacent areas" or "merge candidate areas") to set them as the merge area, and repeating the process of extracting and merging areas that can be merged from areas adjacent to the merge area.

[0041] In this embodiment, only one ONU 20 / RU 30 operates in one merged area. Here, the area that contains the ONU 20 / RU 30 communicating within the merged area is referred to as the "representative area." Here, the RU 30 in the representative area is also referred to as the "representative antenna." Here, the ONU 20 in the representative area is also referred to as the "representative optical communication device."

[0042] The communication control unit 11 selects a representative area within the merged area and controls the RUs 30 / ONUs 20 in the representative area to represent the mobile terminals TE within the merged area. At this time, the communication control unit 11 may control the RUs 30 / ONUs 20 in areas other than the representative area within the merged area to stop or operate with reduced power consumption. For example, if each RU 30 / ONU 20 supports a power-saving operation mode (so-called sleep mode) for power-saving operation, the communication control unit 11 may control the RUs 30 / ONUs 20 in areas other than the representative area within the merged area to operate in the power-saving operation mode. In other words, in the communication system 1 of this embodiment, the creation of the merged area allows the RUs 30 / ONUs 20 in areas other than the representative area to operate with reduced power consumption, thereby enabling the overall system to operate with reduced power consumption compared to conventional systems. The area selected by the communication control unit 11 as the representative area within the merged area is not limited, and any area can be selected. For example, the communication control unit 11 may select the area initially selected as the reference area within the merged area as the representative area.

[0043] As described above, in this embodiment, the communication control unit 11 of the OLT 10 functions as both an allocation unit that performs provisional allocation processing and an area merging unit that performs area merging processing.

[0044] (A-2) Operation of the First Embodiment The operation of the OLT 10 (communication control unit 11) constituting the communication system 1 in the first embodiment (the communication control method according to the embodiment) will be described below.

[0045] FIG. 2 is a flowchart showing an example of the area merge process performed by the communication control unit 11 in the first embodiment.

[0046] 2, after determining the reference area, the communication control unit 11 determines the order of the areas to be merged, and if the total required bandwidth of the reference area and the merge candidate area exceeds the communication rate of the assigned optical communication device, it expands the communication rate to the selectable optical communication unit and merges the reference area and the merge candidate area into a single area. Details are explained below.

[0047] First, at time T1, the communication control unit 11 performs a provisional allocation process and determines a provisional communication rate and communication method for each area (mesh area) taking into consideration the required bandwidth, etc. (S101). After this, the communication control unit 11 proceeds to the area merge process.

[0048] Next, the communication control unit 11 selects one of the areas as a reference area (S102).

[0049] In this embodiment, the communication control unit 11 selects areas at corners from the entire area as candidates for the reference area, and selects one area from the candidates as the reference area. For example, the communication control unit 11 may select the area with the smallest area number from the candidates for the reference area as the reference area.

[0050] Next, the communication control unit 11 searches for a route that allows all areas to be assigned to be drawn in one stroke, starting from the initial reference area, and determines the route obtained as a result of the search (hereinafter also referred to as the "area merge processing route") (S103). At this time, it is desirable for the communication control unit 11 to determine an area merge processing route that will increase the power saving effect of the area merge processing. Details of the area merge processing route will be described later.

[0051] Next, the communication control unit 11 checks whether there are any areas where the allocation status has not been determined from the provisional allocation status (hereinafter, this status will be referred to as "unassigned") (S104), and if there are any unassigned areas, it proceeds to step S105 described below, otherwise it completes the area merge process.

[0052] If there are any unallocated areas remaining, the communication control unit 11 compares the communication method of the unallocated area with that of the reference area as a merge candidate area (S105), and if the communication methods of the two are the same, proceeds to step S106 described below, otherwise proceeds to step S111 described below.

[0053] If the communication methods of the reference area and the merge candidate area are the same, the communication control unit 11 calculates the sum of the required bandwidth of the reference area and the required bandwidth of the merge candidate area (S106).

[0054] Next, the communication control unit 11 compares the calculated total value with the maximum communication rate of the optical communication unit assigned to the reference area (S107), and if the calculated total value does not exceed the maximum communication rate of the reference area, proceeds to step S108 described below, and if it does exceed the maximum communication rate, proceeds to step S109 described below.

[0055] If the calculated total value does not exceed the maximum communication rate of the reference area, the communication control unit 11 merges the reference area and the merge candidate area to form a merged area, and assigns to the merged area the optical communication unit (communication rate / communication method) that was assigned to the original reference area (S108).The communication control unit 11 then ends the processing for the current reference area and returns to step S104.

[0056] On the other hand, if the calculated total value exceeds the maximum communication rate of the reference area, the communication control unit 11 compares the calculated total value with the maximum communication rate of the selectable optical communication unit (S109), and if the calculated total value does not exceed the maximum communication rate of the selectable optical communication unit, proceeds to step S110, which will be described later, otherwise proceeds to step S111, which will be described later.

[0057] If the calculated total value does not exceed the maximum communication rate of the selectable optical communication units, the communication control unit 11 merges the reference area with the merge candidate area, sets the merged area as the reference area, and assigns an optical communication unit with a higher communication rate than the initially assigned optical communication unit from among the selectable optical communication units (S110). If there are multiple selectable optical communication units with a higher communication rate than the initially assigned optical communication unit, the communication control unit 11 may select from the selectable optical communication units the optical communication unit with the next highest communication rate to the optical communication unit originally assigned to the reference area. Furthermore, at this time, the communication control unit 11 may select the optical communication unit with the lowest communication rate among the optical communication units that can cover the calculated total value (the optical communication unit with a communication rate equal to or greater than the total and closest to the total value). Then, the communication control unit 11 ends the processing for the current reference area and returns to step S104.

[0058] If the calculated total value exceeds the maximum communication rate of the selectable optical communication unit, or if the communication methods of the reference area and the merging candidate area are different, the communication control unit 11 does not merge the reference area and the merging candidate area, and continues to assign the optical communication unit currently assigned to the reference area.The communication control unit 11 then marks the reference area as assigned and updates the current merging candidate area as the new reference area.Also, if the reference area is a merging area at this time, the communication control unit 11 determines a representative antenna for the merging area (RU 30 of the area that will become the representative area) and performs communication control for each area according to that determination (S111).The communication control unit 11 then ends the processing for the current reference area and returns to step S104 described above.

[0059] If there is no next unallocated area even when returning to step S104 after the processing of step S108 or step S110 (that is, if all areas have been processed and there is no area that can be the next merging area candidate), the communication control unit 11 may confirm the allocation state of the reference area in its current state and mark it as allocated. In this case, a representative antenna (representative area) within the merging area is determined in the same manner as in step S111.

[0060] Next, a specific example in which the communication control unit 11 of the OLT 10 performs area merge processing will be described with reference to a flowchart shown in FIG.

[0061] FIG. 3 is a diagram showing, in map format, areas A-1 to A-8 constituted by RUs 30-1 to 30-8.

[0062] Here, it is assumed that ONUs 20-1 to 20-8 are arranged under OLT 10, and RUs 30-1 to 30-8 are connected to ONUs 20-1 to 20-8. It is assumed that RUs 30-1 to 30-8 form areas A-1 to A-8 as shown in Fig. 3. In Fig. 3, an area number is added to the upper left of each area. On the map in Fig. 3, areas A-1 to A-8 are arranged so as to form four areas vertically and two areas horizontally. The shape of each area is not limited, but in this description it is assumed to be a square with each side measuring 250 m.

[0063] FIG. 4 is a diagram showing an example of a model of power consumption in the ONU 20 and the RU 30. In FIG.

[0064] For simplicity of explanation, the explanation will be given here assuming that the power consumption of one subscriber (one ONU 20 and one RU 30) can be calculated roughly based on the model in Fig. 4. Note that the model in Fig. 4 is merely an example and is not limiting.

[0065] FIG. 4(a) is a diagram showing an example of a model of power consumption of the ONU 20 (optical communication unit).

[0066] In Figure 4, the power consumption of ONU20 (optical communication unit) is set to 2W when the communication rate is 10Gbps and the communication method is PtMP, and the power consumption of ONU20 (optical communication unit) is set to 5W when the communication rate is 25Gbps and the communication method is PtMP.

[0067] FIG. 4(b) shows a model of the power consumption of the RU 30 (wireless base station). The power consumption of the RU 30 (wireless base station) increases according to the distance (hereinafter referred to as the "longest transmission distance") from the location of the RU 30 to the farthest location within the merged area (hereinafter referred to as the "farthest location"). Therefore, the model in FIG. 4(b) shows the transmission power [W] according to the longest transmission distance (the transmission power when transmitting a wireless signal so that it can reach even from the longest transmission distance). For ease of explanation, this embodiment will be described assuming that the RU 30 is located near the center of each area. In this case, in a single, unmerged area, the RU 30 is located at the center of a 250 m × 250 m square.

[0068] In Figure 4(b), the maximum transmission distance is expressed as a combination of the vertical and horizontal distances from the position of the target RU 30 to the farthest position. For example, in an unmerged, standalone area, the RU is placed at the center of a 250m x 250m square, so the "distance to the vertical edge" and "distance to the horizontal edge" from the position of the RU 30 to the farthest position within that area are both 125m. Therefore, in an unmerged, standalone area, the maximum transmission distance is expressed in the format of Figure 4(b) as "125_125."

[0069] In Fig. 4(b), the transmission power corresponding to the longest transmission distances 125_125, 125_375, 125_625, 125_875, 125_1125, 125_1375, 125_1625, 125_1875, 375_375, 375_625, and 375_875 is shown. For example, in Fig. 4(b), the transmission power corresponding to the longest transmission distance 125_125 is 0.35 W, and the transmission power corresponding to 125_625 is 4.56 W.

[0070] FIG. 5 is a diagram showing an example of power consumption according to the configuration of the merge area.

[0071] FIG. 5(a) shows an example in which the merged area is made up of areas A-1 to A-4 (four vertical areas and one horizontal area). In the example of FIG. 5(a), it is most efficient (to shorten the longest transmission distance) to place the representative antenna in either area A-2 or A-3, which are located near the center of the merged area. The example of FIG. 5(a) shows an example in which RU 30-2 is placed at position PR1, the center point of area A-2, which has the smallest area number among the candidate areas. In this case, the distance from position PR1 to position PE1, which is the longest transmission distance, is "125_625." Therefore, according to the model of FIG. 4(b), the transmission power consumed by RU 30-2 in area A-2 is 4.56 W. If the communication rate / communication method assigned to area A-2 is 10 Gbps / PtMP, the power consumed by ONU 20-1 in area A-2 is 2 W. Therefore, in this case, the total power consumed by wireless communication (RU30-2) and optical communication (ONU20-2) in area A-2 is 2W+4.56W=6.56W.

[0072] FIG. 5(b) shows an example in which the merged areas are areas A-1, A-2, A-5, and A-6 (two vertical areas by two horizontal areas). In the example of FIG. 5(b), the representative antenna may be placed in any of the areas. The example of FIG. 5(b) shows an example in which RU 30-1 is placed at position PR2, the center point of area A-1, which has the smallest area number among the candidate areas. In this case, the distance from position PR2 to position PE2, which is the longest transmission distance, is "375_375." Therefore, according to the model of FIG. 4(b), the transmission power consumed by RU 30-1 in area A-1 is 3.16 W. If the communication rate / communication method assigned to area A-1 is 10 Gbps / PtMP, the power consumed by ONU 20-1 in area A-1 is 2 W. Therefore, in this case, the total power consumed by wireless communication (RU30-1) and optical communication (ONU20-1) in area A-1 is 2W+3.16W=5.16W.

[0073] As shown in Figure 5, in merge areas, the transmission power of wireless communication tends to increase depending on the longest transmission distance, so a "square" or a "rectangle closer to a square" (a rectangle with a smaller difference between the long and short sides) consumes less power overall.

[0074] For example, in the example of Figure 5(a) (4 areas vertically x 1 area horizontally) and the example of Figure 5(b) (2 areas vertically x 2 areas horizontally), the number of areas covered is the same (4), but the square shape of Figure 5(b) has a shorter maximum transmission distance, so it consumes less power overall. Also, even if the merge area is rectangular, if the number of areas covered is the same, the "rectangle that is closer to a square" (a rectangle with a smaller difference between the long and short sides) will have a shorter maximum transmission distance.

[0075] In other words, it is desirable for the communication control unit 11 to determine, as an area merge processing route, an order that makes it easier to merge into a "square" or "rectangle that is as close to a square as possible." For example, when searching for an area merge processing route that allows all areas to be assigned to be drawn in a single stroke starting from the initial reference area, it is desirable for the communication control unit 11 to search for an order that includes as many squares (or rectangles that are closer to a square) as possible on the area merge processing route. A specific example of how the communication control unit 11 determines an area merge processing route will be described later.

[0076] 2, when the communication control unit 11 selects a representative antenna (representative area) for each merged area, it is desirable to select a representative antenna (representative area) that is positioned so as to minimize the maximum transmission distance. For example, it is desirable for the communication control unit 11 to select the RU 30 closest to the center point of the merged area as the representative antenna. If there are multiple RUs 30 closest to the center point, the communication control unit 11 may select the RU 30 with the smallest corresponding area number.

[0077] [First example of area merging process] FIG. 6 is a diagram showing an example of the first area merge process for the required bandwidth of the areas A-1 to A-8.

[0078] Here, as shown in FIG. 6, it is assumed that the required bandwidths corresponding to areas A-1 to A-8 are 1 Gbps, 2 Gbps, 11 Gbps, 11 Gbps, 11 Gbps, 1 Gbps, and 2 Gbps, respectively.

[0079] In the first example of the area merge process, an example will be described in which the communication control unit 11 operates according to the flowchart in FIG. 2 when the areas A-1 to A-8 are in the states shown in FIGS.

[0080] First, in step S101, the communication control unit 11 provisionally allocates a communication rate and a communication method to each mesh area from the requested bandwidth as shown in Fig. 6. At this time, the communication rate / communication method provisionally allocated to areas A-1 to A-8 is assumed to be as shown in Fig. 7.

[0081] FIG. 7 is a diagram showing the results of communication rates / communication methods provisionally assigned by the communication control unit 11 to the areas A-1 to A-8 in the example of the first area merge process.

[0082] Next, the communication control unit 11 selects a reference area by processing in step S102. At this time, the corner mesh areas that are candidates for the reference area are areas A-1, A-4, A-5, and A-8, but area A-1, which has the smallest area number, becomes the reference area.

[0083] Next, in the process of step S103, the communication control unit 11 determines an area merge process route with area A-1 as the first reference area.

[0084] FIG. 8 is a diagram showing an example of an area merge processing route determined by the communication control unit 11. In FIG.

[0085] In FIG. 8, the area merge processing route is shown as a route of areas A-1, A-5, A-6, A-2, A-3, A-7, A-8, and A-4.

[0086] As described above, the communication control unit 11 in this embodiment preferably searches for an order that includes more squares (or rectangles that are closer to squares) on the area merge processing route. Here, the target for determining the area merge processing route is a 4-area by 2-area shape as shown in FIG. 3. Therefore, by determining a route such as that shown in FIG. 8, more squares of 2-area by 2-area shape can be generated on the area merge processing route. In the area merge processing route of FIG. 8, three squares (the squares of areas A-1, A-5, A-6, and A-2, the squares of areas A-2, A-6, A-7, and A-3, and the squares of areas A-3, A-7, A-8, and A-4) are generated. In the case of a 4-area by 2-area shape, there is no route that generates more than three squares, so the route shown in FIG. 8 is suitable as the area merge processing route. Therefore, it is assumed here that the communication control unit 11 has determined the route shown in FIG. 8 as the area merge processing route.

[0087] Next, the communication control unit 11 proceeds to the process of step S104, sets the area A-1 as the reference area, and the area A-5 as the merge candidate area, and proceeds to the process of step S105.

[0088] Next, the communication control unit 11 compares the communication methods of the reference area (area A-1) and the merge candidate area (area A-5) through the process of step S105, and proceeds to step S106 since they are the same communication method.

[0089] Next, the communication control unit 11 obtains 12 Gbps as the total required bandwidth for the reference area (area A-1) and the merge candidate area (area A-5) through the process of step S106.

[0090] Next, in the processing of step S107, the communication control unit 11 compares the total requested bandwidth (12 Gbps) with the communication rate (10 Gbps) of the optical communication unit assigned to the reference area (area A-1), and proceeds to step S109 since the total requested bandwidth (12 Gbps) is larger.

[0091] Next, in the process of step S109, the communication control unit 11 compares the total requested bandwidth (12 Gbps) with the selectable maximum communication rate (25 Gbps), and since the selectable maximum communication rate (25 Gbps) is greater, the process proceeds to step S110.

[0092] Next, in the process of step S110, the communication control unit 11 merges the reference area (area A-1) and the merge candidate area (area A-5), sets the merged area as the reference area, and changes and assigns it to the 25 Gbps optical communication unit.

[0093] Next, the communication control unit 11 returns to the process of step S104, sets the area A-6 as the merge candidate area, sets the merged area (areas A-1 and A-5) as the reference area, and proceeds to step S105.

[0094] Next, the communication control unit 11 compares the communication methods of the reference areas (areas A-1 and A-5) and the merge candidate area (area A-6) in the process of step S105, and proceeds to step S106 since they are the same communication method.

[0095] Next, the communication control unit 11 obtains 23 Gbps as the total required bandwidth for the reference areas (areas A-1 and A-5) and the merge candidate area (area A-6) through the process of step S106.

[0096] Next, in the processing of step S107, the communication control unit 11 compares the total requested bandwidth (23 Gbps) with the communication rate (25 Gbps) of the optical communication unit allocated to the reference area (areas A-1, A-5), and proceeds to step S108 because the communication rate (25 Gbps) of the optical communication unit allocated to the reference area (areas A-1, A-5) is greater.

[0097] Next, in step S108, the communication control unit 11 merges the reference area (areas A-1 and A-5) and the merge candidate area (area A-6) to create a new reference area, allocates a 25 Gbps optical communication unit to the merged area, marks it as allocated, and proceeds to step S104.

[0098] Next, the communication control unit 11 returns to the process of step S104, sets the reference area to the merge area (areas A-1, A-5, A-6), sets the merge candidate area to A-2, and proceeds to the process of step S105.

[0099] Next, in the process of step S105, the communication control unit 11 compares the communication methods of the reference areas (areas A-1, A-5, A-6) and the merge candidate area (area A-2), and proceeds to step S106 since they are the same communication method.

[0100] Next, the communication control unit 11 obtains 25 Gbps as the total required bandwidth for the reference areas (areas A-1, A-5, A-6) and the merge candidate area (area A-2) through the process of step S106.

[0101] Next, in the processing of step S107, the communication control unit 11 compares the total requested bandwidth (25 Gbps) with the communication rate (25 Gbps) of the optical communication unit allocated to the merge candidate area (area A-2), and proceeds to step S108 since the values ​​are the same.

[0102] Next, in step S108, the communication control unit 11 merges the reference area (areas A-1, A-5, A-6) and the merge candidate area (area A-2) to create a new reference area, allocates a 25 Gbps optical communication unit to the merged area, marks it as allocated, and proceeds to step S104.

[0103] Next, in the process of step S104, the communication control unit 11 sets the reference area as the merging area (areas A-1, A-5, A-6, A-2) and the merging candidate area as A-3, and proceeds to the process of step S105.

[0104] In this case, the total required bandwidth of the reference area (areas A-1, A-5, A-6, A-2) and the merge candidate area (A-3) is 36 Gbps, and the maximum communication rate of the selectable optical communication unit is 25 Gbps, so the communication control unit 11 will proceed to step S111.

[0105] Then, in step S111, the communication control unit 11 does not merge the reference areas (areas A-1, A-5, A-6, and A-2) with the merge candidate area (A-3), allocates a 25 Gbps optical communication unit to the reference area, marks the reference area as allocated, and sets RU 30-1 in area A-1 as the representative antenna.The communication control unit 11 then sets area A-3 as the next reference area and proceeds to step S104.

[0106] Then, in step S104, the communication control unit 11 sets area A-3 as the reference area and A-7 as the merge candidate area, and repeats the same process. As a result, the communication control unit 11 further merges areas A-3, A-7, A-8, and A-4 into a single merge area and assigns an optical communication unit with a communication rate of 25 Gbps to the merge area. At this time, the communication control unit 11 also sets RU 30-3 of area A-3 as the representative antenna for the merge area.

[0107] With the above, the communication control unit 11 has completed the merge allocation process for all areas, so there are no unallocated areas and the area merge process ends.

[0108] 9 and 10 are diagrams showing the results after the above-mentioned area merge process (area merge process when the required bandwidths of the areas A-1 to A-8 are in the state shown in FIG. 6) is completed.

[0109] In the above area merge process, a merged area MA3 (a merged area of ​​2 vertical by 2 horizontal) of areas A-1, A-5, A-6, and A-2, and a merged area MA4 (a merged area of ​​2 vertical by 2 horizontal) of areas A-3, A-7, A-8, and A-4 are generated, as shown in Figures 9 and 10. Furthermore, as shown in Figure 9, the communication rate / communication method of these two merged areas MA3 and MA4 is both 25Gbps / PtMP. Furthermore, as shown in Figure 10, the representative antenna of merged area MA3 is RU30-1 in area A-1, and the representative antenna of merged area MA4 is RU30-3 in area A-3.

[0110] In this case, in merged area MA3, the distance from position PR3 of RU 30-1, which serves as the representative antenna, to position PE3, which is the longest transmission distance, is "375_375." Therefore, according to the model in FIG. 4(b), the transmission power consumed by RU 30-1 in area A-1 is 3.16 W. The communication rate / communication method assigned to merged area MA3 is 25 Gbps / PtMP, so the power consumed by ONU 20-1 in area A-1 is 5 W. Therefore, in this case, the total power consumed by wireless communication (RU 30-1) and optical communication (ONU 20-1) in merged area MA3 is 5 W + 3.16 W = 8.16 W. Also in this case, in merged area MA4, the distance from position PR4 of RU 30-3, which serves as the representative antenna, to position PE4, which is the longest transmission distance, is "375_375," and the assigned communication rate / communication method is 25 Gbps / PtMP. Therefore, in merged area MA4, the total power consumed by wireless communication (RU30-3) and optical communication (ONU20-3) is 5W + 3.16W = 8.16W, the same as in merged area MA3. From the above, in the state of Figure 10, the total power consumed by areas A-1 to A-8 is 8.16W × 2 = 16.32W.

[0111] Next, a case will be described in which the communication control unit 11 determines, when determining the area merge processing route in step S103, to simply process in order of area numbers (ascending order) (the area merge processing route is set to a route of areas A-1 to A-8).

[0112] FIG. 11 is a diagram showing the result after the area merge process is completed when the communication control unit 11 determines the area merge process route simply in the order of area numbers (when the required bandwidths of areas A-1 to A-8 are in the state shown in FIG. 6).

[0113] In the above area merge process, a merged area MA5 (a merged area of ​​4 vertical × 1 horizontal) of areas A-1 to A-4 and a merged area MA6 (a merged area of ​​4 vertical × 1 horizontal) of areas A-3 to A-8 are generated, as shown in Figure 11. The communication rate / communication method of these two merged areas MA5 and MA6 is both 25Gbps / PtMP. Furthermore, as shown in Figure 11, the representative antenna of merged area MA5 is RU30-2 in area A-2, and the representative antenna of merged area MA6 is RU30-6 in area A-6.

[0114] In this case, in merged area MA5, the distance from position PR5 of RU 30-2, which serves as the representative antenna, to position PE5, which is the longest transmission distance, is "125_625." Therefore, according to the model in FIG. 4(b), the transmission power consumed by RU 30-2 in area A-2 is 4.56 W. The communication rate / communication method assigned to area A-2 is 25 Gbps / PtMP, so the power consumed by ONU 20-2 in area A-2 is 5 W. Therefore, in this case, the total power consumed by wireless communication (RU 30-2) and optical communication (ONU 20-2) in merged area MA5 is 5 W + 4.56 W = 9.56 W. In addition, in merged area MA6, the distance from position PR6 of RU 30-6, which serves as the representative antenna, to position PE6, which is the longest transmission distance, is "125_625," and the assigned communication rate / communication method is 25 Gbps / PtMP. Therefore, in merged area MA6, the total power consumed by wireless communication (RU30-6) and optical communication (ONU20-3) is 5W + 4.56W = 9.56W, the same as in merged area MA5. From the above, in the state of Figure 11, the total power consumed by areas A-1 to A-8 is 9.56W × 2 = 19.12W.

[0115] From the above, it can be seen that the communication control unit 11 contributes to reducing power consumption by determining the area merge processing route in step S103 as shown in FIG.

[0116] [Second example of area merging process] FIG. 12 is a diagram showing an example of the second area merge process for the required bandwidth of the areas A-1 to A-8.

[0117] Here, as shown in FIG. 12, it is assumed that the required bandwidths corresponding to areas A-1 to A-8 are 1 Gbps, 4 Gbps, 2 Gbps, 3 Gbps, 2 Gbps, 3 Gbps, 5 Gbps, and 5 Gbps, respectively.

[0118] In the second example of the area merge process, an example will be described in which the communication control unit 11 performs the area merge process according to the flowchart in FIG. 2 when the situations of the areas A-1 to A-8 are as shown in FIGS.

[0119] First, in step S101, the communication control unit 11 provisionally allocates a communication rate and a communication method to each area from the requested bandwidth as shown in Fig. 12. At this time, it is assumed that the communication rate / communication method provisionally allocated to areas A-1 to A-8 are as shown in Fig. 13.

[0120] Next, the communication control unit 11 selects a reference area through the process of step S102. At this time, the communication control unit 11 selects area A-1 as the reference area, as in the case of the example of the first area merge process.

[0121] Next, in step S103, the communication control unit 11 determines an area merge processing route using area A-1 as the first reference area. At this time, the area merge processing route determined by the communication control unit 11 is assumed to be the order shown in FIG. 8, as in the first example of the area merge processing.

[0122] Next, the communication control unit 11 proceeds to the process of step S104, sets the area A-1 as the reference area, and the area A-5 as the merge candidate area, and proceeds to the process of step S105.

[0123] Next, the communication control unit 11 compares the communication methods of the reference area (area A-1) and the merge candidate area (area A-5) through the process of step S105, and proceeds to step S106 since they are the same communication method.

[0124] Next, the communication control unit 11 obtains 3 Gbps as the total required bandwidth for the reference area (area A-1) and the merge candidate area (area A-5) through the process of step S106.

[0125] Next, in step S107, the communication control unit 11 compares the total requested bandwidth (3 Gbps) with the communication rate (10 Gbps) of the optical communication unit allocated to the reference area (area A-1), and proceeds to step S108 because the communication rate (10 Gbps) of the optical communication unit allocated to the reference area (area A-1) is greater.

[0126] Next, in step S108, the communication control unit 11 merges the reference area (area A-1) and the merge candidate area (area A-5) to create a new reference area, allocates a 10 Gbps optical communication unit to the merged area, marks it as allocated, and proceeds to step S104.

[0127] Next, the communication control unit 11 returns to the process of step S104, sets the merge area (areas A-1 and A-5) as the reference area, sets A-6 as the merge candidate area, and repeats the same process.

[0128] Here, the communication method is the same for the reference area (areas A-1, A-5) and the merge candidate area (area A-6), and the total required bandwidth is 6 Gbps, which does not exceed the communication rate (10 Gbps) of the optical communication unit assigned to the reference area (areas A-1, A-5), so the communication control unit 11 proceeds to step S108.

[0129] Next, in step S108, the communication control unit 11 merges the reference area (areas A-1 and A-5) and the merge candidate area (area A-6) to create a new reference area, allocates a 10 Gbps optical communication unit to the merged area, marks it as allocated, and proceeds to step S104.

[0130] Next, the communication control unit 11 returns to the process of step S104, sets the reference area to the merge area (areas A-1, A-5, A-6), sets the merge candidate area to A-2, and repeats the same process.

[0131] Here, the communication method is the same for the reference area (areas A-1, A-5, A-6) and the merge candidate area (area A-2), and the total required bandwidth is 10 Gbps, which does not exceed the communication rate (10 Gbps) of the optical communication unit assigned to the reference area (areas A-1, A-5), so the communication control unit 11 proceeds to step S108.

[0132] Next, in step S108, the communication control unit 11 merges the reference area (areas A-1, A-5, A-6) with the merge candidate area (area A-2) to create a new reference area, allocates a 10 Gbps optical communication unit to the merged area, marks it as allocated, and proceeds to step S104.

[0133] Next, the communication control unit 11 returns to the process of step S104, sets the reference area to the merge area (areas A-1, A-5, A-6, A-2), sets the merge candidate area to A-3, and repeats the same process.

[0134] Here, the communication method is the same for the reference area (areas A-1, A-5, A-6, A-2) and the merge candidate area (area A-3), and the total required bandwidth is 12 Gbps, which exceeds the communication rate (10 Gbps) of the optical communication unit assigned to the reference area (areas A-1, A-5, A-6, A-2), so the communication control unit 11 proceeds to step S109.

[0135] Next, in the process of step S109, the communication control unit 11 compares the total requested bandwidth (12 Gbps) with the selectable maximum communication rate (25 Gbps), and since the selectable maximum communication rate (25 Gbps) is greater, the process proceeds to step S110.

[0136] Next, in step S110, the communication control unit 11 merges the reference area (areas A-1, A-5, A-6, A-2) with the merge candidate area (area A-3), sets the merged area as the reference area, and changes and assigns it to the 25 Gbps optical communication unit.

[0137] Next, the communication control unit 11 returns to the process of step S104, sets area A-7 as the merge candidate area, sets the merged areas (areas A-1, A-5, A-6, A-2, and A-3) as the reference area, and proceeds to step S105.

[0138] Next, the communication control unit 11 returns to the process of step S104, sets the reference area to the merge area (areas A-1, A-5, A-6, A-2, and A-3), sets the merge candidate area to A-7, and repeats the same process.

[0139] Here, the communication method is the same for the reference area (areas A-1, A-5, A-6, A-2, A-3) and the merge candidate area (area A-7), and the total required bandwidth is 17 Gbps, which does not exceed the communication rate (25 Gbps) of the optical communication unit assigned to the reference area (areas A-1, A-5, A-6, A-2, A-3), so the communication control unit 11 proceeds to step S108.

[0140] Next, in step S108, the communication control unit 11 merges the reference area (areas A-1, A-5, A-6, A-2, A-3) with the merge candidate area (area A-7) to create a new reference area, allocates a 25 Gbps optical communication unit to the merged area, marks it as allocated, and proceeds to step S104.

[0141] Next, the communication control unit 11 returns to the process of step S104, sets the reference area to the merge area (areas A-1, A-5, A-6, A-2, A-3, and A-7), sets the merge candidate area to A-8, and repeats the same process.

[0142] Here, the communication method is the same for the reference area (areas A-1, A-5, A-6, A-2, A-3, A-7) and the merge candidate area (area A-8), and the total required bandwidth is 22 Gbps, which does not exceed the communication rate (25 Gbps) of the optical communication unit assigned to the reference area (areas A-1, A-5, A-6, A-2, A-3, A-7), so the communication control unit 11 proceeds to step S108.

[0143] Next, in step S108, the communication control unit 11 merges the reference area (areas A-1, A-5, A-6, A-2, A-3, A-7) with the merge candidate area (area A-8) to create a new reference area, allocates a 25 Gbps optical communication unit to the merged area, marks it as allocated, and proceeds to step S104.

[0144] Next, the communication control unit 11 returns to the processing of step S104, sets the reference area to the merge area (areas A-1, A-5, A-6, A-2, A-3, A-7, A-8), sets the merge candidate area to A-4, and repeats the same processing.

[0145] Here, the communication method is the same for the reference area (areas A-1, A-5, A-6, A-2, A-3, A-7, A-8) and the merge candidate area (area A-4), and the total required bandwidth is 25 Gbps, which does not exceed the communication rate (25 Gbps) of the optical communication unit allocated to the reference area (areas A-1, A-5, A-6, A-2, A-3, A-7, A-8), so the communication control unit 11 proceeds to step S108.

[0146] Next, in the processing of step S108, the communication control unit 11 merges the reference area (areas A-1, A-5, A-6, A-2, A-3, A-7, A-8) with the merge candidate area (area A-4) to create a new reference area, allocates a 25 Gbps optical communication unit to the merged area, marks it as allocated, and proceeds to step S104.

[0147] With the above, the communication control unit 11 has completed the merge allocation process for all areas, so there are no unallocated areas and the area merge process ends.

[0148] 14 and 15 are diagrams showing the results after the above-mentioned area merge process (area merge process when the required bandwidths of the areas A-1 to A-8 are in the state shown in FIG. 12) is completed.

[0149] In the above area merge process, a merged area MA7 (a merged area of ​​4 vertical x 2 horizontal) of areas A-1 to A-8 is generated as shown in Figures 14 and 15. Also, as shown in Figure 14, the communication rate / communication method of this merged area MA7 is 25Gbps / PtMP. Furthermore, as shown in Figure 15, the representative antenna of merged area MA7 is RU30-2 in area A-2.

[0150] In this case, in merged area MA7, the distance from position PR7 of RU 30-2, which serves as the representative antenna, to position PE7, which is the longest transmission distance, is "375_625." Therefore, according to the model in FIG. 4(b), the transmission power consumed by RU 30-2 in area A-2 is 5.97 W. Here, the communication rate / communication method assigned to merged area MA7 is 25 Gbps / PtMP, so the power consumed by ONU 20-2 in area A-2 is 5 W. Therefore, in this case, the total power consumed by wireless communication (RU 30-2) and optical communication (ONU 20-2) in merged area MA3 is 5 W + 5.97 W = 10.97 W. From the above, in the state of FIG. 15, the total power consumed by areas A-1 to A-8 as a whole is 10.97 W.

[0151] Next, we will explain an example in which, when the communication control unit 11 determines the area merge processing route in step S103, it simply processes in order of area number (ascending order) and does not change the communication rate provisionally assigned to each area.

[0152] Figures 16 and 17 are figures showing the results of the area merge process in an example of the second area merge process in which the communication control unit 11 determines the area merge process route simply in the order of area numbers and does not change the communication rates provisionally assigned to each area.

[0153] In the above area merge process, as shown in Figures 16 and 17, a merged area MA8 (a merged area of ​​4 vertical x 1 horizontal) of areas A-1 to A-4 and a merged area MA9 (a merged area of ​​3 vertical x 1 horizontal) of areas A-5 to A-7 are generated. Furthermore, in the above area merge process, area A-8 is not merged with any other areas. Furthermore, the communication rate / communication method of these two merged areas MA8 and MA9 and the single area A-8 are all 10Gbps / PtMP. Furthermore, as shown in Figure 17, the representative antenna of merged area MA8 is RU30-2 in area A-2, and the representative antenna of merged area MA9 is RU30-6 in area A-6.

[0154] In this case, in merged area MA8, the distance from position PR8 of RU 30-2, which serves as the representative antenna, to position PE8, which is the longest transmission distance, is "125_625," so according to the model in Figure 4(b), the transmission power consumed by RU 30-2 in area A-2 is 4.56 W. Here, the communication rate / communication method assigned to area A-2 is 10 Gbps / PtMP, so the power consumed by ONU 20-2 in area A-2 is 2 W. Therefore, in this case, the total power consumed by wireless communication (RU 30-2) and optical communication (ONU 20-2) in merged area MA8 is 2 W + 4.56 W = 6.56 W.

[0155] In this case, in merged area MA9, the distance from position PR9 of RU 30-6, which serves as the representative antenna, to position PE9, which is the longest transmission distance, is "125_375." Therefore, according to the model in Figure 4(b), the transmission power consumed by RU 30-6 in area A-6 is 1.76 W. Here, the communication rate / communication method assigned to area A-6 is 10 Gbps / PtMP, so the power consumed by ONU 20-2 in area A-2 is 2 W. Therefore, in this case, the total power consumed by wireless communication (RU 30-6) and optical communication (ONU 20-6) in merged area MA9 is 2 W + 1.76 W = 3.76 W.

[0156] Furthermore, in this case, in area A-8, the distance from position PR10 of RU 30-8 to position PE10, which is the longest transmission distance, is "125_125," so according to the model in FIG. 4(b), the transmission power consumed by RU 30-8 in area A-8 is 0.35 W. Here, the communication rate / communication method assigned to area A-8 is 10 Gbps / PtMP, so the power consumed by ONU 20-8 in area A-8 is 2 W. Therefore, in this case, the total power consumed by wireless communication (RU 30-8) and optical communication (ONU 20-8) in area A-8 is 2 W + 0.35 W = 2.35 W.

[0157] From the above, in the state of FIGS. 16 and 17, the total power consumed in the areas A-1 to A-8 is 6.56W+3.76W+2.35W=12.67W.

[0158] From the above, it can be seen that the communication control unit 11 contributes to reducing power consumption by determining the area merge processing route in step S103 as shown in FIG. 8 and further changing the communication rate during the area merge processing.

[0159] (A-3) Effects of the First Embodiment According to the first embodiment, the following effects can be achieved.

[0160] In the first embodiment, even if the communication rates assigned to each area (each ONU 20) are different, as long as the communication method is the same, the communication control unit 11 assigns the highest possible communication rate (an optical communication unit with a higher communication rate), making it possible to generate a merged area in which a greater number of areas are merged. As a result, the communication system 1 of the first embodiment achieves effects such as reduced power consumption for the entire system.

[0161] Furthermore, when determining an area merge processing route, the communication control unit 11 of the first embodiment determines a route that reduces the transmission power of the RU 30. This results in the communication system 1 of the first embodiment achieving effects such as reduced power consumption in the entire system.

[0162] (B) Second embodiment A second embodiment of a communication system, a communication control method, and a master station communication device according to the present invention will be described below in detail with reference to the drawings.

[0163] (B-1) Configuration and operation of the second embodiment The overall configuration of the communication system 1A of the second embodiment can also be shown using FIG.

[0164] In the following, only the differences between the first and second embodiments will be described. Note that the reference numerals in parentheses in Fig. 1 are used only in the second embodiment.

[0165] The communication system 1A of the second embodiment differs from the first embodiment in that the optical communication network system 100 is replaced with an optical communication network system 100A. The optical communication network system 100A of the second embodiment also differs from the first embodiment in that the OLT 10 is replaced with an OLT 10A. The OLT 10A of the second embodiment also differs from the first embodiment in that the communication control unit 11 is replaced with a communication control unit 11A.

[0166] The communication control unit 11A differs from the first embodiment in part of the area merge processing.

[0167] The communication control unit 11 in the first embodiment searches for an area merge processing route for the entire area to be subjected to the area merge processing (hereinafter referred to as "all target areas"), and performs the area merge processing using the searched area merge processing route. In contrast, the communication control unit 11A in the second embodiment sets a window of a predetermined shape (hereinafter referred to as "area merge processing window") for all target areas, and performs the area merge processing in units of the area merge processing window within all target areas.

[0168] As mentioned above, in a merge area, the transmission power of wireless communication tends to increase according to the longest transmission distance, so a "square" or a "rectangle closer to a square" (a rectangle with a smaller difference between its long and short sides) consumes less power as a whole system. Therefore, it is desirable for the area merge processing window to also be a "square" or a "rectangle closer to a square." For example, if the area merge processing window itself is square, the merge area generated as a result of the area merge processing is also more likely to be square.

[0169] Here, an example will be described in which the communication control unit 11A performs the area merge process on all target areas as shown in FIG.

[0170] FIG. 18 is a diagram showing, in the form of a map, areas A-1 to A-36 configured by RUs 30-1 to 30-36 (ONUs 20-1 to ONUs 20-36).

[0171] Here, it is assumed that ONUs 20-1 to 20-36 are arranged under OLT 10, and RUs 30-1 to 30-36 are connected to ONUs 20-1 to 20-36. It is assumed that RUs 30-1 to 30-36 form areas A-1 to A-36 as shown in Fig. 18. In Fig. 18, an area number is added to the upper left of each area. On the map in Fig. 18, areas A-1 to A-36 are arranged so as to form 6 areas vertically and 6 areas horizontally. The shape of each area is not limited, but here, it is assumed that each area is a square with each side measuring 250 m, as in the first embodiment.

[0172] Here, the communication control unit 11A sets multiple area merge processing windows, each consisting of three vertical areas and three horizontal areas, for all target areas, and performs area merge processing for each area merge processing window. Fig. 18 shows an example in which all target areas are covered by four area merge processing windows W1 to W4. For example, in Fig. 18, area merge processing window W1 is set for areas A-1 to A-3, A-7 to A-9, and A-13 to A-15.

[0173] That is, in this embodiment, the communication control unit 11A performs the same area merge processing as in the first embodiment for each of the area merge processing windows W1 to W4.

[0174] In this case, the communication control unit 11A may perform the same process as in the first embodiment for searching for an area merge processing route within the area merge processing window. In the second embodiment, the area merge processing route is searched only for the shape of the area merge processing window, so a preset, standard route may be used as the area merge processing route.

[0175] FIG. 19 is a diagram showing an example of an area merge processing route that the communication control unit 11A determines for the area merge processing window W1.

[0176] In FIG. 19, the area merge processing route determined by the communication control unit 11A for the area merge processing window W1 is shown as a route through areas A-1, A-7, A-8, A-2, A-3, A-9, A-15, A-14, and A-13.

[0177] FIG. 20 shows an example of the result when the communication control unit 11A performs the area merge processing on the area merge processing window W1.

[0178] FIG. 20 shows an example in which, as a result of the area merge process, all areas in all area merge process windows W1 are merged into one merge area MA11.

[0179] In this case, in merged area MA11, the distance from position PR11 of RU 30-8, which serves as the representative antenna, to position PE11, which is the longest transmission distance, is "375_375." Therefore, according to the model in FIG. 4(b), the transmission power consumed by RU 30-8 in area A-8 is 3.16 W. If the communication rate / communication method assigned to area A-8 is 25 Gbps / PtMP, the power consumed by ONU 20-8 in area A-8 is 5 W. Therefore, in this case, the total power consumed by wireless communication (RU 30-8) and optical communication (ONU 20-8) in merged area MA11 is 5 W + 3.16 W = 8.16 W.

[0180] In the example of Figure 20, the maximum transmission distance is the same as in the case of 2 vertical areas x 2 horizontal areas shown in Figure 5(b), so even though the number of covered areas is 9, the power consumption is about the same as in the case of 2 vertical areas x 2 horizontal areas. This is because by setting the area merge processing window to "odd area x odd area," the center point of all hourly areas can be aligned with the position of the representative antenna. In this way, in communication system 1A, by setting the area merge processing window to odd area x odd area, the power saving effect can be further improved.

[0181] (B-2) Effects of the Second Embodiment According to the second embodiment, in addition to the effects of the first embodiment, the following effects can be achieved.

[0182] In the second embodiment, the search for the area merge processing route is performed in area merge processing window units, which makes it possible to reduce the amount of search processing for the area merge processing route, unlike in the first embodiment. For example, if the entire target range is wide, the search processing for the area merge processing route alone requires an enormous amount of calculation. However, in the second embodiment, the area merge processing route only needs to be determined within the standard area merge processing window as described above, which makes it possible to reduce the calculation resources required for the communication control unit 11A.

[0183] (C) Other embodiments The present invention is not limited to the above-described embodiments, and may include modified embodiments such as those exemplified below.

[0184] (C-1) In each of the above embodiments, an optical communication network system 100 using a PON as a transmission path is applied as a communication network system connecting between RU30 and DU / CU50, but the network configuration applied to the communication network system is not limited to PON and various network configurations (for example, a branchable digital leased line or a bandwidth-controllable IP network, etc.) can be applied.

[0185] (C-2) In the above embodiments, the communication control unit 11 of the OLT 10 has been described as functioning as an allocation means for performing provisional allocation processing and an area merging means for performing area merging processing, but the allocation means and area merging means may be mounted on a device other than the OLT 10. For example, the allocation means and area merging means may be mounted on the DU / CU 50.

[0186] (C-3) In the second embodiment, an example was shown in which an area merge processing window was configured as 3 areas vertically and 3 areas horizontally, but the communication control unit 11A may combine area merge processing windows of a plurality of different shapes to perform area merge processing for all target areas. For example, the communication control unit 11A may combine an area merge processing window of 3 areas vertically and 3 areas horizontally with an area merge processing window of 2 areas vertically and 2 areas horizontally to cover all target areas. [Explanation of symbols]

[0187] 1...Communication system, 10...OLT, 11...Communication control unit, 13...OLT concentrator, 14...10G transceiver, 15...Transceiver, 16...100G transceiver, 17...Transceiver, 18...200G media converter, 20...ONU, 21...User side interface, 22...Transceiver, 30...Terminal, 60...Core network, 70...Splitter, 80...Optical fiber, 100...Optical communication network system, A...Area (mesh area), TE...Mobile terminal

Claims

1. A communication network system comprising a plurality of wireless antenna devices for transmitting and receiving wireless signals to and from a mobile terminal, a signal processing device for processing transmission and reception of signals to and from the mobile terminal via the wireless antenna devices, and data transmission between each of the wireless antenna devices and the signal processing devices, wherein the communication network system has a slave station communication device connected to each of the wireless antenna devices, a master station communication device connected to each of the signal processing devices, and a transmission path connecting the master station communication device to each of the slave station communication devices, an allocation means for allocating a communication rate and a communication method to an area corresponding to each of the wireless antenna devices; an area merging means for selecting any one of the areas as a reference area, and, if the communication method of the reference area and the merging candidate area adjacent to the reference area match and the sum of the required bandwidth of the reference area and the required bandwidth of the merging candidate area is equal to or less than a selectable communication rate, performing an area merging process for merging the reference area and the merging candidate area into one merged area and allocating a communication rate and a communication method to the merged area; A communication system comprising:

2. 2. The communication system according to claim 1, wherein, when the sum is greater than the current communication rate, the area merging unit assigns a communication rate greater than the sum to the merged area.

3. The communication system according to claim 1, characterized in that the area merge means determines an area merge processing route that describes the order in which an area to be initially selected as the reference area and an area to be selected as the merge candidate area are selected, and attempts the area merge processing along the determined area merge processing route.

4. 4. The communication system according to claim 3, wherein the area merging unit determines the area merging process route so that the transmission power of the radio antenna device is reduced as a result of the area merging process.

5. 5. The communication system according to claim 4, wherein the area merging means determines a route that generates a greater number of squares or a predetermined shape closer to a square as the area merging processing route.

6. The communication system according to claim 3, characterized in that the area merge means sets a plurality of area merge processing windows for all areas to be subject to the area merge processing, determines the area merge processing route for each area merge processing window, and performs the area merge processing.

7. 7. The communication system according to claim 6, wherein the area merge processing window has a square shape or a predetermined shape closer to a square.

8. A communication control method performed by a communication system comprising: a plurality of wireless antenna devices that transmit and receive wireless signals to and from a mobile terminal; a signal processing device that processes transmission and reception of signals to and from the mobile terminal via the wireless antenna devices; and a communication network system that transmits data between each of the wireless antenna devices and the signal processing device, the communication network system having a slave station communication device connected to each of the wireless antenna devices, a master station communication device connected to the signal processing device, and a transmission path that connects the master station communication device to each of the slave station communication devices, The communication system includes an allocation means and an area merging means, the allocation means allocates a communication rate and a communication method to an area corresponding to each of the wireless antenna devices; The area merging means selects one of the areas as a reference area, and if the communication method of the reference area and the merge candidate area adjacent to the reference area match and the sum of the required bandwidth of the reference area and the required bandwidth of the merge candidate area is equal to or less than a selectable communication rate, performs area merging processing to merge the reference area and the merge candidate area into one merged area and assign a communication rate and a communication method to the merged area. A communication control method comprising:

9. In a communication network system for transmitting data between a plurality of wireless antenna devices that transmit and receive wireless signals to and from mobile terminals, and a signal processing device that processes transmission and reception of signals to and from the mobile terminals via the wireless antenna devices, a master station communication device connects the signal processing device to slave station communication devices connected to each of the wireless antenna devices via a transmission path, an allocation means for allocating a communication rate and a communication method to an area corresponding to each of the wireless antenna devices; an area merging means for selecting one of the areas as a reference area, and, if the communication method of the reference area and the merging candidate area adjacent to the reference area match and the sum of the required bandwidth of the reference area and the merging candidate area is equal to or less than a selectable communication rate, performing an area merging process of merging the reference area and the merging candidate area into one merged area and allocating a communication rate and a communication method to the merged area; A master station communication device comprising:

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